Author Topic: Brand new Magic Pie 5 short circuit  (Read 4323 times)

Offline Orlandoas

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Brand new Magic Pie 5 short circuit
« on: July 11, 2016, 12:39:54 AM »
Hi I write you because today after connect for first time the battery (48V 20Ah lifePo4) to my brand new Magic Pie 5 black motor and after several successfull tests of the throttle, brakes lever and cruiser function, the motor has produced an electric short circuit.
After unplug the battery and verify the right voltage (48V) I have reconnected the circuit and the throttle, brakes lever and cruiser function still works but the lights over the throttle remains in red .

What I can do for evaluate the potential damages?, is dangerous to use the motor after the experimented short circuit? how I can prevent the return of the failure

Thanks!!

Offline Bikemad

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Re: Brand new Magic Pie 5 short circuit
« Reply #1 on: July 11, 2016, 09:41:24 AM »
Hi Orlando andto the forum.

I have a few questions for you:

     1) What makes you so certain that "the motor has produced an electric short circuit", could it just be a poor connection on a battery wire etc?

     2) Was there a loud pop, arcing sound, blown fuse, sparks, hot wires, smoke or a burning smell?

     3) Did the wheel lock up instantly or become very stiff to turn by hand?

     4) Assuming all three battery gauge LEDs were initially on, did they all go off together, or did they gradually go off one at a time?

     5) Do you have a fuse and/or a switch wired into the battery supply, if so, what is the current and voltage rating?

     6) Were you actually riding the bike when it happened, or just testing the motor with the wheel off the ground?

     7) Did you have the Bluetooth App running on an Android phone or the BAC-601 LCD Smart Display Unit connected to show any error codes or messages?

A direct short circuit will draw a lot of current and can sometimes produce a very loud bang and very bright spark (which also generates a huge amount of instant heat):





If the battery was only reading 48V, this seems very low for a 48V LiFePO4 battery, as fully charged they are usually nearer 58V. The low voltage might explain why you only have the single red LED showing on the battery gauge (instead of the Red, Amber and Green LEDs all being lit).

If your charger has a switch to select the correct input voltage, make sure it is in the correct position to suit your mains supply voltage, I'm in the UK, so mine is set in the 220V position:



If you have a 110V mains supply and the charger is set to 220V (like the one shown above) you will need to recharge the battery with the voltage selector switch in the correct position.
You can use the tip of a pen or a cocktail stick etc. to slide the switch over to the correct position  ;)

Make sure that the main battery wires, and the wires for the horn, lights, pedelec sensor and reverse are not exposed and touching together.



All unused wires should be safely insulated to prevent contact with adjacent wires or metal components on the bike.

Fortunately, as the controller and motor are both still working correctly, it would appear that they were not damaged by the incident.

Unfortunately, without knowing what has actually caused the fault, you might not be able to prevent it from happening again. :(

Alan
 
« Last Edit: July 02, 2017, 04:44:25 PM by Bikemad »